2012-04-08

After a couple years of use my bike horn stopped making any noise when air flowed through. Even after a fresh air tank refill to 80 PSI, it would only whine quietly for a second before hissing to depletion.

I confirmed that the volume knob was not limiting airflow,

and that there were no kinks in the hose beneath the air tank's bottle cap cover,

so I turned to the FAQ:

If it's still 'windy' try turning back cap to the left until it pops off. Then check to make sure membrane is flat & clean (spiders have been known to move in). Reassemble, then push & turn back cap all the way back on.

Sure enough, that round piece on the back of the horn pops off after a slight turn to the left:

I didn't see any spiders inside,

but I ran water through the tube to clean out any dirt—

—and that did the trick. It's now loud as new.